That's a good question. It isn't "cheap". I would have to dig up the bills to get the figures exact. I remember that it varied, depending on how old (far back) your current unit is by serial number. The laser upgrade was an additional charge to the "normal" upgrade at that time. Seems like it was about $175 for that upgrade. Other upgrades are more or less, depending on how far back you are (in two or three steps)
But before you say "Wow, that is a lot, I could buy another whole brand X for that", consider this. The upgrade totally replaces the internal electronics -- microwave diodes, receivers and logic board. It isn't just a firmware flash upgrade. They also replace the case if it is scratched or damaged (or missing a knob) And, the warrantee is reset to full term again. Your unit comes back in a brand new box with a new owner's manual too.
So, it is a lot like leasing except you don't have to turn it in at the end. If you want to upgrade to the next technology they have, you can send it in....turn around both times was only about 2 days. If not, you can keep it the way it is.
The first upgrade came about 1998 where they dramatically improved sensistivity, reduced falsing, added the "sliding KA" band. Definately worth it at the time.
The second (for me) was when they added Laser reception. That one added about an eighth of an inch to the bottom where the new circuitry was added. You can see it in the picture. This made it a bit heavier and required larger suction cups to hold it on the window....included of course. The current model has been downsized back to the original size and is lighter and the cups are back to the smaller size. This upgrade also added non-volatile memory so that it would power back up in the same mode you powered down in.
Now that I live in the Atlanta area, I get about 80% of the attacks via laser. Laser detection, albeit hit and miss, a must have here.
Now I skipped a few of the updates they offered over time...The website allows you to kick in your serial number and they give you the exact changes that are available as compared to what you have already...They even go as far as recommending that you upgrade or just wait for the next big change. (as in the current situation for my oldest one)
I also like knowing that they track the owners of each unit in their system so that if a V1 comes in for upgrade and it didn't come from the registered owner, they have a protocol in place to identify if the unit is stolen or not.
(and pass that info on for action)
(no I don't work for V1, but I sure could be a salesman for them)